This application relies for priority upon Korean Patent Application No. 2001-340, filed on Jan. 4, 2001, the contents of which are herein incorporated by reference in their entirety.
1. Field of the Invention
The present invention relates to the field of semiconductor manufacturing and, more particularly, to a ball grid array (BGA) package including a heat sink.
2. Description of the Related Art
A transistor is a basic unit of integrated circuits on a semiconductor chip. As the number of transistors on a single semiconductor chip increases several problems arise due to heat dissipation. That is, heat is inevitably generated during the operation of integrated circuit devices.
As the number of gates increases, the generated heat also increases and damages the chip, shortening the lifetime of the semiconductor chip. For every 10xc2x0 C. increase in the temperature of the semiconductor chips, the failure rate of the chips doubles. In the case of a CMOS semiconductor chip, the clock speed also decreases by 1 MHz. Therefore, removal or dissipation of the heat from the devices more and more important.
In the conventional semiconductor package, the heat generated from the semiconductor chip is emitted through two routes. The first route is through external connection terminals of the package and the second route is through the surface of the package. In order to more effectively dissipate the heat, a heat sink can be attached to the package. In a ball grid array (BGA) package including an encapsulating resin formed by molding semiconductor chip with a plastic resin, the heat sink is attached directly to the encapsulating resin of the package. In this case, the heat generated from the chip is conducted to the heat sink via the encapsulant and dissipated to the outside by convection.
Since the encapsulating resin has poor thermal conductivity, heat cannot be effectively dissipated through the heat sink attached to the encapsulating resin.
The present invention contemplates a semiconductor package structure that more effectively dissipates the heat generated by the semiconductor chip.
According to an embodiment of the present invention, a semiconductor package comprises a semiconductor chip and a printed circuit board. The printed circuit board comprises a board body. An upper wiring layer is formed on the upper surface of the board body and includes a chip-mounting portion for mounting the semiconductor chip, board pads formed around the chip-mounting portion and electrically connected to said semiconductor chip, and an upper heat dissipation layer around said chip-mounting portion. Further, a lower wiring layer including a lower heat dissipation layer is formed on the lower surface of the board body. First heat-dissipating via holes are formed through the board body between the chip-mounting portion and the lower heat dissipation layer and are filled with a thermally conductive material for dissipating heat from the chip through the board body toward the lower wiring layer. Second heat-dissipating via holes are formed through the board body below said upper heat dissipation layer and are filled with a thermally conductive material for dissipating heat generated from the chip through the board body toward the upper heat dissipation layer.